I have been talking about this a lot for summer and looking for options. Most of these would swamp me. But my versions include the Ripskirt (yeah, it has a waist, but the waist is super loose and the fabric ultra casual), and my Comrags dress. A "pant" version is the wide leg crop chambray. They feel (and quite honestly, look) quite PJ-like -- in the way that some of these dresses look like nighties.
My grandma and mother wore housedresses. Grandma's were shirtwaists with ditsy prints. My mother had some of the caftans in the 70s.
ETA: the Comrags is kind of magical because it is capable of working in the house but also it looks really nice for actual going-out events. It's a kind of seersucker nonwrinkling cotton, which makes it really versatile.
